SCIENCE ELECTRON CONFIGURATION

• Principal energy levels contains sublevels designated by the letters spdf
• electron spin on its own axis in one of only two directions, clockwise and counterclockwise
• aufbau principle is a useful memory device for determining the order in which the sublevels fill
• electron configuration the assignment of all the electrons in an tom into specific shells and sublevels
• 1817, Johann Wolfgang Dobereiner a professor at the university of jena in germany
• the heaviest and the lightest ones these groups were known as Dobereiner's triads
• 1864, John Alexander Reina Newlands an english chemist reported his law of octaves
• Dmitri Mendeleev and Julius Lothar Meyer work independently and proposed that when elements were arranged in order of increasing atomic mass
• Meyer established the periodicity of elements
• mendeleev used the elements chemical properties to establish the patterns
• Henry G. J. Moseley atomic number rather than atomic mass was used to arrange the elements
• basis for the periodic table is the periodic law
• period rows in the periodic table
• vertical columns which consist of elements having similar chemical properties are known as group or families
• in 1985 IUPAC proposed a new labeling system to resolve the controversy between the american and european systems
• the groups be designated by the numerals 1 to 18
• elements can be classified as metals and non metals based on their properties
• most elements are metal
• to the right of them are the nonmetals
• elements on the left side of the line are called metalloids or semimetals and have properties intermediate between those of the metals and nonmetals
• periodic law states that when elements are arranged in order of increasing atomic number, their physical and chemical properties shows a periodic pattern
• Groups in the periodic table

  • Group 1A - Alkali metals
  • Group 2A - Alkali Earth Metals
  • Group 3A - Boron Family
  • Group 4A - Carbon Family
  • Group 5A - Nitrogen Family
  • Group 6A - Oxygen Family/Chalcogens
  • Group 7A - Halogens
  • Group 8A - Noble Gases
• atomic number always the same with electron and proton
• atomic mass add proton and neutron
• number of e always the same with atomic number and proton
• number of p always the same with atomic number and electron
• number of n subtract atomic number and atomic mass to get this
• Sublevels

  • S - 2
  • P - 6
  • D - 10
  • F - 14
• Aufbau Principle

  • 1s2
  • 2s2
  • 2p6
  • 3s2
  • 3p6
  • 4s2
  • 3d10
  • 4p6
  • 5s2
  • 4d10
  • 5p6
  • 6s2
  • 4f14
  • 5d10
  • 6p6
  • 7s2
  • 5f14
  • 6d10
  • 7p6